Creating Dialogbased Windows Application (4) / 创建基于对话框的Windows应用程序（四）Edit Control、Combo Box的应用、Unicode转ANSI、Open File Dialog、文件读取、可变参数、文本框自动滚动 / VC++, Windows
创建基于对话框的Windows应用程序（四）—— Edit Control、Combo Box的应用、Unicode转ANSI、Open File Dialog、文件读取、可变参数、自动滚动
之前的介绍中，我们用到了Button、Static Text、Checkbox这三个控件。这一节中我们将学习使用Edit Control（编辑框）、Combo Box控件，其中还包括Unicode转ANSI的方法、创建Open File Dialog、 读取文件、可变参数（这里用于生成日志）、文本框自动滚动的功能等。
24、首先切换到Reasource View（Ctrl+Shift+E），找到待修改的主窗体，并从Toolbox（Ctrl+Atl+X）中添加Edit Control、Combo Box、Button控件如下：
其中Edit Box的Properties设置为：
点击Combo Box右边三角箭头可以调整其下拉框的大小：
更改控件ID后记得在reasource.h文件中将多余的定义删除或注释掉：
注意：在以代码形式打开reasource.h或.rc文件后若要回到Reasource View中查看编辑，须先将打开的各相关文件关闭。
25、在被调用的命令消息响应函数（Dlg_OnCommand）中添加对Browse按钮的响应动作。
点击Browse按钮将创建Open File Dialog，并将选取的文件路径显示在一旁的Combo Box中：
其中WideCharToMultiByte函数实现了Unicode到ANSI的转换。
26、实现在Edit Control中添加文本并实现自动滚动：
其中当“count == 0”时，将屏蔽可变参数的使用。关于可变参数的使用可以在后面的代码中看到。
按下Open按钮，将根据Combo Box中的路径读取文件，并按ANSI文本格式显示在Edit Control中：
1 #include <Windows.h> 2 #include <windowsx.h> 3 #include <tchar.h> 4 #include <Shobjidl.h> 5 #include <mutex> 6 #include <string> 7 #include "Resource.h" 8 9 // Sets the dialog box icons 10 inline void chSETDLGICONS(HWND hWnd, int idi) { 11 SendMessage(hWnd, WM_SETICON, ICON_BIG, (LPARAM) 12 LoadIcon((HINSTANCE)GetWindowLongPtr(hWnd, GWLP_HINSTANCE), 13 MAKEINTRESOURCE(idi))); 14 SendMessage(hWnd, WM_SETICON, ICON_SMALL, (LPARAM) 15 LoadIcon((HINSTANCE)GetWindowLongPtr(hWnd, GWLP_HINSTANCE), 16 MAKEINTRESOURCE(idi))); 17 } 18 19 // The normal HANDLE_MSG macro in WindowsX.h does not work properly for dialog 20 // boxes because DlgProc returns a BOOL instead of an LRESULT (like 21 // WndProcs). This chHANDLE_DLGMSG macro corrects the problem: 22 #define chHANDLE_DLGMSG(hWnd, message, fn) \ 23 case (message): return (SetDlgMsgResult(hWnd, uMsg, \ 24 HANDLE_##message((hWnd), (wParam), (lParam), (fn)))) 25 26 // Main dialog 27 HWND g_hDlg; 28 29 std::mutex g_add; 30 // Adds a string to the "TextView" edit control 31 // Disable "..." when "count == 0", otherwise 32 // "count" can't be smaller than the (formatted) string size 33 void AddText(DWORD count, PCTSTR pszFormat, ...) { 34 std::lock_guard<std::mutex> lock(g_add); 35 36 static std::string text; 37 38 if (count == 0) 39 { 40 text.append(pszFormat); 41 } 42 else 43 { 44 va_list argList; 45 va_start(argList, pszFormat); 46 TCHAR *sz = new TCHAR[count]; 47 memset(sz, '\0', count); 48 _vstprintf_s(sz, count, pszFormat, argList); 49 va_end(argList); 50 text.append(sz); 51 delete[] sz; 52 } 53 54 HWND hEdit = GetDlgItem(g_hDlg, IDC_TEXTVIEW); 55 ::SendMessage(hEdit, 56 WM_SETREDRAW, FALSE/*关闭重绘*/, 0); 57 58 //Edit_SetText(hEdit, text.c_str()); 59 //::SetDlgItemText(g_hDlg/*包含Edit Control主窗口的句柄*/, 60 //IDC_TEXTVIEW/*Edit Control资源的编号*/, text.c_str()/*要输出的信息*/); 61 ::SendMessage(hEdit, WM_SETTEXT, false, (LPARAM)text.c_str()); 62 63 int iLine = (int)::SendMessage(GetDlgItem(g_hDlg, 64 IDC_TEXTVIEW)/*Edit Control的句柄*/, EM_GETLINECOUNT, 0/*忽略*/, 0/*忽略*/); 65 ::SendMessage(hEdit, EM_LINESCROLL, 0/*水平滚动的字符个数*/, 66 iLine/*垂直滚动的行数*/); 67 size_t iOutputLen = _tcslen(pszFormat); 68 ::SendMessage(hEdit, EM_SETSEL, iOutputLen/*要选中字符的起始位置*/, 69 iOutputLen/*要选中字符的结束位置*/); 70 71 ::SendMessage(hEdit, WM_SETREDRAW, TRUE/*打开重绘*/, 0); 72 } 73 74 INT_PTR WINAPI NewDlg_Proc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam) { 75 switch (uMsg) 76 { 77 case WM_CLOSE: 78 EndDialog(hWnd, 0); 79 break; 80 } 81 82 return(FALSE); 83 } 84 85 void Dlg_OnCommand(HWND hWnd, int id, HWND hWndCtl, UINT codeNotify) { 86 HRESULT hr; 87 IFileDialog *pfd = NULL; 88 LPWSTR filePath = L""; 89 TCHAR file[MAX_PATH] = { 0 }; 90 COMDLG_FILTERSPEC rgSpec[] = 91 { 92 { TEXT(L"文本文档"), TEXT(L"*.txt") }, 93 { TEXT(L"所有文件"), TEXT(L"*.*") } 94 }; 95 TCHAR* buffer; 96 DWORD filesize; 97 HWND hWndComboBox; 98 static unsigned int num = 1; 99 switch (id) { 100 case IDC_CHECKONTOP: 101 SetWindowPos(hWnd, IsDlgButtonChecked(hWnd, IDC_CHECKONTOP) 102 ? HWND_TOPMOST : HWND_NOTOPMOST, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE); 103 break; 104 case IDC_BROWSE: 105 hr = CoCreateInstance(CLSID_FileOpenDialog, 106 NULL, 107 CLSCTX_INPROC_SERVER, 108 IID_PPV_ARGS(&pfd)); 109 FILEOPENDIALOGOPTIONS dwFlags; 110 hr = pfd->GetOptions(&dwFlags); 111 hr = pfd->SetOptions(dwFlags | FOS_FORCEFILESYSTEM); 112 hr = pfd->SetFileTypes(2, rgSpec); 113 hr = pfd->SetFileTypeIndex(1); 114 hr = pfd->Show(hWnd); 115 IShellItem * pShellItem; 116 hr = pfd->GetResult(&pShellItem); 117 if (hr == S_OK) 118 { 119 hr = pShellItem->GetDisplayName(SIGDN_DESKTOPABSOLUTEPARSING, &filePath); 120 WideCharToMultiByte(CP_ACP, WC_COMPOSITECHECK, filePath, MAX_PATH, file, 121 sizeof(file), NULL, NULL); 122 SetDlgItemText(hWnd, IDC_EDITCOMBO, file); 123 } 124 break; 125 case IDOPEN: 126 GetDlgItemText(hWnd, IDC_EDITCOMBO, file, _countof(file)); 127 hWndComboBox = GetDlgItem(hWnd, IDC_EDITCOMBO); 128 SendMessage(hWndComboBox, CB_ADDSTRING, 0, (LPARAM)file); 129 HANDLE hFile; 130 DWORD readsize; 131 hFile = CreateFile(file, GENERIC_READ, FILE_SHARE_READ, NULL, 132 OPEN_EXISTING, NULL, NULL); 133 if (hFile == INVALID_HANDLE_VALUE) 134 { 135 CloseHandle(hFile); 136 break; 137 } 138 filesize = GetFileSize(hFile, NULL); 139 buffer = new char[filesize + 1]; 140 ReadFile(hFile, buffer, filesize, &readsize, NULL); 141 buffer[filesize] = 0; 142 AddText(MAX_PATH + 32, _T("NO.%03d %s\r\n\r\n"), num, file); 143 num++; 144 AddText(0, buffer); 145 delete[] buffer; 146 AddText(0, "\r\n\r\n"); 147 CloseHandle(hFile); 148 break; 149 case IDCANCEL: 150 SendMessage(hWnd, WM_CLOSE, 0, 0); 151 break; 152 153 } 154 } 155 156 BOOL Dlg_OnInitDialog(HWND hWnd, HWND hWndFocus, LPARAM lParam) { 157 g_hDlg = hWnd; 158 159 chSETDLGICONS(hWnd, IDI_ICON1); 160 161 SetWindowPos(hWnd, HWND_TOPMOST, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE); 162 CheckDlgButton(hWnd, IDC_CHECKONTOP, BST_CHECKED); 163 164 return(TRUE); 165 } 166 167 INT_PTR WINAPI Dlg_Proc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam) { 168 switch (uMsg) 169 { 170 chHANDLE_DLGMSG(hWnd, WM_INITDIALOG, Dlg_OnInitDialog); 171 chHANDLE_DLGMSG(hWnd, WM_COMMAND, Dlg_OnCommand); 172 case WM_CLOSE: 173 EndDialog(hWnd, 0); 174 break; 175 } 176 177 return(FALSE); 178 } 179 180 int WINAPI WinMain(HINSTANCE hinstExe, HINSTANCE, PTSTR pszCmdLine, int) { 181 DialogBoxParam(hinstExe, MAKEINTRESOURCE(IDD_DIALOG), 182 NULL, Dlg_Proc, _ttoi(pszCmdLine)); 183 184 return(0); 185 }
26、此时按下F5 Start Debugging，可以检验所需功能皆已完成。
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